[turbofan] Use FastNewClosureStub if possible.

src/compiler/js-generic-lowering.cc

Index: src/compiler/js-generic-lowering.cc
diff --git a/src/compiler/js-generic-lowering.cc b/src/compiler/js-generic-lowering.cc
index 55a594c5dd6bd148863255bd7bd8d0a83458a8ca..a0ca17d977fb1c3de628954027ad8fd129e1189c 100644
--- a/src/compiler/js-generic-lowering.cc
+++ b/src/compiler/js-generic-lowering.cc
@@ -413,6 +413,14 @@ void JSGenericLowering::LowerJSStoreContext(Node* node) {
 }
 
 
+void JSGenericLowering::LowerJSCreateClosure(Node* node) {
+  CreateClosureParameters p = CreateClosureParametersOf(node->op());
+  node->InsertInput(zone(), 1, jsgraph()->HeapConstant(p.shared_info()));
+  node->InsertInput(zone(), 2, jsgraph()->BooleanConstant(p.pretenure()));
+  ReplaceWithRuntimeCall(node, Runtime::kNewClosure);
+}
+
+
 void JSGenericLowering::LowerJSCreateCatchContext(Node* node) {
   Unique<String> name = OpParameter<Unique<String>>(node);
   node->InsertInput(zone(), 0, jsgraph()->HeapConstant(name));